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Stairs' detection and avoidance using nav2d

asked 2017-11-02 08:19:20 -0600

gerson_n gravatar image

updated 2018-05-16 00:56:03 -0600

Hi to all,

Since I sucessfully implemented nav2d to my own robot, I've been thinking about translate it to another place where there are downstairs. I've read nav2d documentation without find any clue about that and I don't know if it already has an implementation for Operator node nor costmap.

In this case would be useful some kind of layer that identifies for costmap an amount of -z readings. From what I've read, geometry_msgs/Pose2D for nav2d_msgs doesn't use z axis, so that could be a problem. I'm using a kinect and I think isn't necessary using an extra ultrasonic sensor pointing below for this.

I hope you can enlighten me about that.

Thanks in advance


I've found an interesting package that could work for me: cliff_detector. Fortunatelly, it has support for kinetic version which is just what I'm using, and It's made for a kinect sensor, too.

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answered 2017-11-03 03:33:33 -0600

Sebastian Kasperski gravatar image

Well, nav2d is a package for 2D navigation, and stairs are a very 3D-type of thing! ;)

However, the costmap_2d (which is used by the Operator) can use 3D readings and include them in the local map. You may have a look at the documentation there. With this the Operator could treat downstairs as obstacles and avoid them, but they will still not be represented in the global map.

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Nice, thanks again @Sebastian Kasperski. I'll take a look at costmap2d

gerson_n gravatar image gerson_n  ( 2017-11-03 07:43:35 -0600 )edit

I think cliff_detector would be a solution for stairs avoidance. Have you worked with that before? It uses RANSAC algorithm, so maybe identifies cliffs like map bounds.

gerson_n gravatar image gerson_n  ( 2017-11-03 09:34:45 -0600 )edit

No, I haven't used it. When deciding on a solution, keep in mind that you will have to add any detected stairs to the global map as well, else the Navigator will always try to send your robot down the stairs.

Sebastian Kasperski gravatar image Sebastian Kasperski  ( 2017-11-08 03:51:49 -0600 )edit

@gerson_n were you able to apply it?

hdbot gravatar image hdbot  ( 2019-03-26 11:26:33 -0600 )edit

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Asked: 2017-11-02 08:19:20 -0600

Seen: 398 times

Last updated: May 16 '18